A former political leader in Falls Church pleaded guilty Thursday to a total of five charges related to sexual molestation of young girls.

The plea from Michael Gardner, 51, ended one trial underway in Arlington County and closed out the need for another scheduled for November.

Gardner, ex-chairman of the Falls Church Democratic Party, pleaded guilty to four counts of aggravated sexual battery and also pleaded guilty to one count of object sexual penetration, said Loudoun County Chief Deputy Commonwealth’s Attorney Nicole Wittmann.

One case involved the assault of three young girls whom authorities said were molested by Gardner during sleepovers at his home, including for his daughter’s 10th birthday slumber party.

Gardner was arrested shortly after the June 2011 party. He stood trial, was convicted and sentenced to 22 years, but his conviction was later overturned by the Virginia Supreme Court.

The court said character evidence in Gardner’s defense was wrongly excluded and a new trial was set.

Gardner faced a separate trial after a now-adult victim came forward saying Gardner had similarly molested her while she was a minor.

His pleas ended both cases.

Gardner agreed Thursday to a sentence of 20 years, Wittmann said. She said Gardner, who will be on probation for life, will be a registered sex offender.

The Loudoun prosecutor’s office took the case because Arlington’s commonwealth’s attorney knew the Gardners, presenting a potential conflict of interest.